Alzheimer's disease (AD) is a neurodegenerative disease which significantly increases with age. Currently there is no cure for Alzheimer's disease and ultimately it results in death. It is estimated that in 2014, there were 5.2 million Americans living with Alzheimer's disease, two thirds consisting of women. One in six women are estimated to be at risk for developing Alzheimer's. Alzheimer's disease is the 6th leading cause of death in the United States, and approximately 500,000 people die each year from the disease. It is the most expensive condition in the U.S. to treat, with the direct cost to the U.S. of caring for those with Alzheimer's exceeding $200 billion, including $150 billion in costs to Medicare and Medicaid. It is estimated that these costs will reach $1.2 trillion in 2050, as it is expected that 16 million Americans will be living with Alzheimer's disease at that time.
Alzheimer's disease was first described by the Bavarian psychiatrist Alois Alzheimer in 1907. It is a progressive neuropsychiatric disorder which begins with short term memory loss and proceeds to loss of cognitive functions, disorientation, impairment of judgment and reasoning and, ultimately, dementia. AD is the most common form of dementia. There is currently no treatment for AD that can reverse or slow down the disease progression. AD represents a major health problem and an effective treatment of the disease would represent a major breakthrough.
The clinical manifestations of Alzheimer's disease begin with subtle short-term memory deficits and depressive symptoms, followed by orientation and language difficulties. Intellectual functions progressively disappear and patients become entirely dependent, typically surviving in this devastating state for more than a decade. Death generally occurs from a secondary infection, frequently from pneumonia or urinary infection. The duration of the disease from the appearance of the first symptoms and the manifestation of dementia varies between 5 and 20 years. Clinical diagnosis of Alzheimer's disease often occurs long after the onset of the disease. It is usually first noticed by immediate family members who detect problems with short-term memory and unusual behavior. Confirmation is achieved post-mortem by detecting the presence of the pathological hallmarks of the disease, amyloid plaques and neurofibrillary tangles.
The mainstream current FDA-approved pharmacological treatment for Alzheimer's disease is to ameliorate cognitive decline by restoring neurotransmitter signaling between neurons. Four of the five medications approved by the FDA for prescription to Alzheimer's disease patients are aimed at increasing extracellular levels of acetylcholine by delaying its degradation (the acetylcholinesterase inhibitors: tacrine, rivastigmine, galantamine and donepezil). The fifth approved drug is memantine, a partial antagonist for the ionotropic glutamate NMDA receptor. Memantine presumably reduces calcium-mediated glutamate excitotoxicity, hence slowing synaptic and neuronal loss characteristically observed in the Alzheimer's diseased brain. Although these treatments have proven to maintain cognitive function in Alzheimer's diseased patients, the therapeutic effect is transient and primarily symptomatic. These treatments are not mechanism-based and do not seem to have any disease-modifying effects. Moreover, no significant proof supports that these drugs play a role in the prevention of cognitive decline or the reversal of pathological hallmarks and neurodegeneration in Alzheimer's disease.
“The causes of Alzheimer's disease remain unknown and there is no cure.” August 2014 issue of the Journal of Alzheimer's Disease. Previous suggestions that particular genetic factors were involved in Alzheimer's disease, e.g. the E4 allele, and associations of APOE and the disease, have been shown to be incorrect, as there is no evidence for linkage between Alzheimer's disease and APOE.
There is, as yet, no cure for Alzheimer's disease despite concerted efforts and investment by industry. There is therefore a long-felt but unsolved need for a method and system to prevent Alzheimer's disease in order to spare tens of millions of individuals the terrible fate otherwise awaiting them.